A black-and-white developer which is used for processing silver halide photographic materials contains dihydroxybenzenes, 3-pyrazolidones or p-aminophenols as a developing agent, an alkali agent and a sulfurous acid salt as the basic components.
Photographic characteristics required for silver halide photographic materials, particularly black-and-white negative light-sensitive materials for cameras, include sensitivity, gradation and granularity. These characteristics are required to be enhanced. Thus, naturally, the components of a developer for use in photographic processing of silver halide photographic materials are limited.
In the case of silver halide photographic materials for news photographs and publications which must be processed relatively rapidly by the use of an automatic developing machine, the material is made relatively soft so as to impart sensitization suitability due to the controlling of developing time of the material. Such relatively soft light-sensitive materials, however, have disadvantages in that the mechanical strength during processing is not sufficiently high and the drying speed is seriously lowered. To solve these problems, it becomes necessary to harden the light-sensitive material. That is, it is established practice at the present time that a dialdehyde-based hardening agent is added to a processing solution (i.e., a developer). In addition, developing hardening acts to accelerate rinsing of the light-sensitive material which has been developed and fixed. Thus, increased developing hardening is desired.
For the developing hardening reaction to proceed sufficiently, it is desirable for the developer to have a high pH value beyond the specified level. In the processing of light-sensitive materials such as an X-ray photographic material in which high contrast and high image density are needed, no problem arises in increasing developing activity by increasing the pH value of the developer. On the other hand, in the processing of general light-sensitive materials, particularly the black-and-white negative light-sensitive materials for cameras in which the contrast is low and granularity is important, the necessary characteristics are not always obtained unless the pH of the developer is within a relatively low range in view of developing activity.
However, in the pH range designed for the hardening reaction, deterioration due to oxidation is serious because the pH value is higher than that of a developer used in the developing processing not using an automatic developing machine (e.g., conventional tank development or plate development) and, furthermore, the developer is stirred in a developer tank of the automatic developing machine. Thus, the stability of the developer becomes more important. At present, however, a developer having sufficiently high stability has not been obtained.
Furthermore, in the pH range of the developer in which the hardening reaction occurs, it is difficult to balance fog and sensitivity and also to balance toe sensitivity and gradation, and a completely different technique is needed, unlike a developer for tank development which does not contain any hardening agent.